The social behaviour of farm animals is an important aspect of their sentience.
It underlines their ability to think and also the significance of their social and emotional bonds.

Farm animals in natural conditions have quite complex social lives and social conventions.
Living in groups requires awareness and understanding of the behaviour of others, and the ability to manage social interactions.
It involves recognition of different individuals (including those of other species, such as humans), communication, selecting mates and looking after young.

Animal behaviour scientists have studied and compared the social lives of farm animals in natural, semi-natural and intensive farming conditions.
In spite of thousands of years of domestic use, and decades of intensive breeding and farming, experts agree that the basic behaviour patterns and motivation of farm animals has changed little compared to their wild ancestors.
Farmed pigs and chickens can revert to wild behaviour without difficulty.

Cattle, pigs, sheep and chickens naturally live in herds or flocks.
They coordinate their activities of moving pasture, resting, feeding or grazing.
They usually form social hierarchies, and in free-ranging conditions these are maintained by some animals avoiding or being submissive to others.
They may also form friendship pairs.
Scientists do not understand in detail how these social arrangements are formed, but the dominance hierarchy may be the result of a number of social "agreements".

Many commercial farming methods cause social problems by joining unnaturally large numbers of animals together, changing or splitting up groups and mixing them with other unfamiliar animals for the convenience of farming practice.
Animals are often sold on to different farms at different stages of their rearing or reproductive lives, to join unfamiliar animals.
Unnatural social groups make conflict more likely.
The animals may not be able to recognise all the others in their flock, herd or group and fights, fear and stress are likely to be caused when animals are removed or new animals join.

The confined conditions and overcrowding may often make it impossible for weaker animals to avoid or get away from more dominant animals.
Unfortunately, the usual intensive farming solution to these problems caused by keeping unnaturally large numbers of animals together has been to confine them to cages and stalls!

Pigs

When foraging for food pigs often have special neighbours.
Pigs that know each other greet my making nose-to-nose contact and groom each other if they know each other very well.

Pigs may be able to recognise and remember up to 20-30 individuals.
In a social group they establish stability by understanding each other's behaviour and by working out which are the more aggressive or dominant.

Sheep

Sheep are very good at distinguishing between and remembering other animals.
They can remember images of 50 sheep faces for up to two years.
They can also recognise animals from their profiles after they have learned to recognise them from the front view.

Researchers have concluded that sheep have a highly developed requirement for social interaction and a sophisticated sense of social awareness.

Chickens

Intensive farming keeps thousands of chickens together in one place.
In the wild chickens would live in mixed-sex flocks of 4-30 adults.
These birds would stay close together and sychronise activities such as foraging, resting and preening.

Domestics hens seem to have flockmates, preferring to be close to familiar birds, avoiding unfamiliar ones.

Feather pecking, common in commercial egg farming, is never seen in wild chickens.